More experimental tonearms. I am going off on a tangent here, pun intended. These have nothing to do tangential tracking. I believe it's about using string to deal with tracking force to lessen the moment of inertia from the ubiquitous counterweight. As you can tell, some of these arms use recycle parts from other arms.

It was inspired by the(47 Labs) RS Labs RS-A1 tonearm. Here's the text on the website via Google Translate:

I'm not sure any of these work at all as tonearms. Apparently this is just one big experiment and we never saw the final product as can be seen in this series pictures in historical context: What disappointment!

That's a loaded question. Please go back to earlier posts to explore more. The RS Labs examples are not intended to correct offset angles or to reduce tracking error so it's really not about tangency. But it is intended to reduce skating force.